This invention relates to a pixelated, thin-film-based, fluid-assay, active-matrix structure, and more particularly to a row-and-column micro-structure of active, individually digitally-addressable pixels which have been prepared on a supporting substrate as “blank slates” for later, selective, assay-specific, assay-site affinity functionalization, also referred to as pixel functionalization, to enable the performance of at least one kind of a fluid-material assay. This micro-structure is also referred to herein as an assay-affinity-lacking micro-structure, in which each pixel is spoken of as possessing an assay-affinity-lacking sensor, as will be explained hereinbelow.
Preferably, the invention takes the form of a relatively inexpensive, consumer-level-affordable, thin-film-based assay structure which features a low-cost substrate that will readily accommodate low-cost, and preferably “low-temperature-condition”, fabrication thereon of substrate-supported matrix-pixel “components”. “Low temperature” is defined herein as a being a characteristic of processing that can be done on substrate material having a transition temperature (Tg) which is less than about 850° C., i.e., less than a temperature which, if maintained during sustained material processing, would cause the subject material to lose dimensional stability. Accordingly, while the matrix-pixel technology of this invention, if so desired, can be implemented on more costly supporting silicon substrates, the preferred supporting substrate material is one made of lower-expense glass or plastic materials. The terms “glass” and “plastic” employed herein to describe a preferred substrate material should be understood to be referring also to other suitable “low-temperature materials Such substrate materials, while importantly contributing on one level to relatively low, overall, end-product cost, also allow specially for the compatible employment, with respect to the fabrication of supported pixel structure, of processes and methods that are based on amorphous, micro-crystal and polysilicon thin-film-transistor (TFT) technology. In particular, these substrate materials uniquely accommodate the use of the just-mentioned TFT technology in such a way that electrical, mechanical and electromagnetic field-creating devices—devices that are included variously in the structure of the invention—can be fabricated simultaneously in a process flow which is consistent with the temperature tolerance of such substrate materials.
Regarding the preference herein for the use of low-temperature TFT technology, and briefly describing aspects of that technology, low-temperature TFT devices are formed through deposition processes that deposit silicon-based (or other-material-based, as mentioned below herein, and as referred to at certain points within this text with the expression “etc.”) thin film semiconductor material (which, for certain applications, may, of course, later be laser crystallized). This is quite different from classic silicon CMOS device technology that utilizes a single-crystal silicon wafer bulk material as its semiconductor material. While the resulting TFT devices may not have the switching speed and drive capability of transistors formed on single-crystal substrates, TFT transistors can be fabricated cheaply with a relatively few number of process steps. Further, thin-film deposition processes permit TFT devices to be formed on alternate substrate materials, such as transparent glass substrates, for use, as an example, in liquid crystal displays. In this context, it will be understood that TFT device fabrication may variously involve the use typically of amorphous Si (a-Si), of micro-crystalline Si, and or of polycrystalline Si formed by low-temperature internal crystalline-structure processing of amorphous Si. Such processing is described in U.S. Pat. No. 7,125,451 B2, the contents of which patent are hereby incorporated herein by reference.
For the sake simply of convenience of expression regarding the present invention, and in order to emphasize the “low-temperature” formation possibility which is associated with the invention in its preferred form, all aspects of assay-matrix pixel fabrication and resulting structure are referred to herein in the context and language of “low-temperature silicon on glass or plastic” construction, and also in the context and language of “low-temperature TFT and Si technology”.
Returning now to a general description of the features of the present invention, a precursor pixel-matrix structure, which is formed utilizing the above-mentioned low-temperature TFT and Si technology, is provided preferably on a glass or plastic substrate, whereby, ultimately, and completely under the control of a recipient-user's selection, each pixel in that matrix is individually and independently affinity-functionalizable to display an affinity, i.e., an attraction, for at least one specific fluid-assay material, and following such functionalization, and the subsequent performance of a relevant assay, individually and independently digitally readable to assess assay results. The term “functionalization” herein, and each like term, means preparing a site within a pixel to possess an affinity, i.e., an attraction, for a particular fluid assay material.
The invention thus takes the form of an extremely versatile and relatively low-cost matrix assay precursor structure, also referred to herein interchangeably as a microstructure. It is a precursor structure in the sense that, as has just been mentioned above, it is not yet an assay-material-specific-functionalized assay structure, i.e., it is not yet assay-affinity functionalized, and until so functionalized, has no ability to attract any specific assay material. As will become apparent from the invention description which is provided herein, the structure of this invention is therefore one which is providable, as a singularity, to a user, in a special status which enables that user selectively to functionalize pixels in the structure, with great versatility, to perform one, or even plural different (as will be explained), type(s) of fluid-material assay(s).
While there are many ways in which the core characteristics of this invention may be visualized, one way of thinking about it is to recognize its analogy to those kinds of commercial products which are considered to be “staples” in commerce, i.e., base products which lie as key ingredients in a vast range of final products into which they are processed and incorporated. The structure of the present invention, in the context of its associated field of art and technology regarding the performances of fluid-material assays, is such a product. This analogy should clearly stand out as one reads the full description of the invention presented herein.
There is certain terminology, other than the “low-temperature” terminology defined above, which is employed in the description and characterization of this invention which should here be explained.
The concepts of, and terms relating to, “digital addressability” and “energizing” expressed herein are intended to refer to computer-controlled addressability and energizing.
The term “active-matrix” as used herein refers to a pixelated structure wherein each pixel is controlled by and in relation to some form of digitally-addressable electronic structure, which structure includes digitally-addressable electronic switching structure, defined by one or more electronic switching device(s), operatively associated, as will be seen, with also-included pixel-specific assay-sensor structure and pixel-bathing electromagnetic field-creating, or functionalizing, structure—all formed preferably by low-temperature TFT and Si technology as mentioned above.
The term “bi-alternate” refers to a possible matrix condition enabled by the present invention, wherein every other pixel in each row and column of pixels may selectively become commonly functionalized for one, specific type of a fluid-material assay. This condition effectively creates, across the entire area of the overall matrix of the invention, two differently functionalizable submatrices of pixels (what can be thought of as a two-assay, single-overall-matrix condition).
The term “tri-alternate” refers to a similar condition, but one wherein every third pixel in each row and column may selectively become commonly functionalized for one, specific type of a fluid-material assay. This condition effectively creates, across the entire area of the overall matrix, three, differently functionalizable submatrices of pixels (what can be thought of as a three-assay, single-overall-matrix condition). Individual digital addressability of each pixel permits these and other kinds of matrix-distributed functionalization options, if desired.
Other kinds of submatrices are, of course, possible, and one other type of submatrix arrangement is specifically mentioned hereinbelow. Whenever a user elects to employ a submatrix functionalization approach regarding an overall matrix made in accordance with the present invention, that approach may be employed to enable either (a) several, successive same-assay-material matrix-assay uses with the same overall matrix, or (b) several successive different-assay-material submatrix-assay uses also employing the same overall matrix.
It should be apparent that the use of a submatrix functionalization approach with respect to the matrix structure of the present invention enables a user to elect to perform selected assays at different pixel-distribution “granularities”.
With respect to the concept of assay-site functionalization, except for the special features enabled by practice of the present invention that relate (a) to “pixel-specific” functionalization capability, and (b) functionalization under the “control” of a “digitally energized and character-managed”, “assay-site-bathing” ambient electromagnetic field of a selected nature, assay-site functionalization is in all other respects essentially conventional in practice. Such functionalization is, therefore, insofar as its conventional aspects are concerned, well known to those generally skilled in the relevant art, and not elaborated herein, but for a brief mention later herein noting the probable collaborative use, in many functionalization procedures, of conventional flow-cell assay-sensor-functional processes.
While ultimately-enabled functionalization specificity, i.e., assay-affinity specificity for a particular selected assay site (resident within a given pixel), in accordance with practice of the present invention in certain instances, is generally and largely controlled by ambient “bathing” of that site with selected-nature electromagnetic-field energy received from an invention-prepared, digitally-energized, appropriately positionally located electromagnetic field-creating subcomponent, it turns out that site-precision specificity is not a critical operational factor. In other words, it is entirely appropriate if the entirety of a pixel becomes ultimately affinity “functionalized”. Accordingly, various terminology referring to pixel functionalization and to assay-site functionalization is used herein interchangeably.
Each prepared “precursor” pixel, which is an active-matrix pixel as that language is employed herein, includes, as was mentioned, at least one, digitally-addressable, assay-affinity-lacking sensor which is designed to possess, or host, at least one ultimately to-be-functionalized fluid-assay site that will have and display an affinity for a selected, specific fluid-assay material. Each such assay site, in its non-functionalized, precursor condition, is referred to herein variously as a non-affinity-functionalized, or non-assay-functionalized, assay site. In its functionalized state, it is referred to variously as an affinity-functionalized assay site, as an assay-functionalized assay site, and as an affinity assay site. Each such pixel also includes, as earlier indicated, an “on-board”, digitally-addressable, assay-site-bathing (also referred to as “pixel-bathing”), electromagnetic-field-creating structure (part of a thin-film electronic switching structure) which, among other things, is controllably energizable, as will be explained, (a) to assist in the affinity-functionalizing of such an assay site for the performance of a specific kind of fluid-material assay, and (b) to assist (where appropriate) in the output reading of the result of a particular assay. This field-creating structure, which, in terms of its functionalizing capability, is also referred to as an affinity functionalizer, and as an affinity-establishing functionalizer, is capable, via the inclusion therein of suitable, different, field-creating subcomponents, and in accordance with the present invention, of producing, as an ambient, pixel-bathing field environment within its respective, associated pixel, any one or more of (a) a light field, (b) a heat field, and (c) a non-uniform electrical field.
The invention, as suggested above, thus offers an extremely flexibly employable, staple-like, pixelated, precursor, fluid-assay, active-matrix structure, or micro-structure, wherein the individual pixels are not initially pre-ordained to function responsively with any specific fluid-assay material, but rather are poised with a readiness to have their respective, associated assay sensors later user-functionalized to respond with specificity to such an assay material.
In the proposed row-and-column arrangement of precursor assay pixels prepared in accordance with the practice of the present invention, each pixel includes a least one, and may include more than one, assay sensor(s), with each such assay sensor being ultimately functionalizable to host, or possess, at least one, but optionally and selectively plural, assay-material-specific assay sites that are functionalized appropriately for such materials.
Additionally, and with respect to the important and striking versatility which is offered by the present invention, and thinking about the concept generally mentioned above regarding submatrices, it is entirely possible for a user of the subject precursor structure of this invention to create plural, different unified areas (i.e., unified lower-pixel-count submatrices defined by next-adjacent, side-by-side pixels) within the overall, entire matrix structure which have their respective submatrix pixels functionalized to respond to a specific type of fluid-assay material, with each such different submatrix area being capable of responding to respective, different assay materials.
It should be understood that while the structure of the present invention, as will become apparent, is built in such a fashion that all addressable field-creating subcomponents within each pixel are remotely digitally addressable to assist in pixel functionalization, actual overall functionalization of an assay site on a pixel assay sensor may involve, additionally, as mentioned briefly earlier, the utilization of conventional flow-cell processes in order to implement a full correct functionalization procedure. For example, where an assay site in such a pixel is to become functionalized to respond in a DNA-type assay, conventional flow-cell technology may be used, in cooperation with functionalization assistance provided by the on-board field-creating structure, to carry out such full assay-site functionalization.
As will become apparent, one especially interesting feature of this invention is that it introduces the possibility of deriving assay-result data, including kinetic assay-reaction data, effectively along plural, special axes not enabled by prior art devices. For example, and with respect to the performance, or performances, of a selected, particular type of fluid-material assay, pixels in a group included in full matrix, or in a smaller-pixel-count submatrix, may be functionalized for assay use utilizing plural different levels, or intensities, of functionalization-assist fields, such as intensity-differentiated heat and/or non-uniform electrical fields. Such differentiated field-intensity functionalization can yield, following an assay, information regarding how an assay's results are affected by such “field-differentiated” pixel functionalization. Similarly, assay results may be observed by reading pixel output responses successively under different (changed) ambient field conditions that are then presented as “bathing” fields seriatim to information-outputting pixels.
Further in relation to the versatile utility of the present invention following user-pixel-functionalization and the performance of a relevant assay, and with respect specifically to the reading-out of completed-assay response information, time-axis output data may easily be gathered on a pixel-by-pixel basis via pixel-specific, digital output sampling.
Regarding the making of a precursor matrix micro-structure as proposed by the present invention, an important point to note is that the processes, procedures and methodologies which are employed specifically to fabricate this precursor structure may be drawn entirely from now-conventional micro-array fabrication practices, such as the earlier-mentioned TFT, Si, low-temperature, and low-cost-substrate technology practices, well known to those generally skilled the art. Accordingly, further details of these practices, which form no part of the present invention, are not set forth herein. Those generally skilled in the relevant art will understand, from a reading of the present specification text, taken along with the accompanying drawing figures, exactly how to practice the present invention, i.e., will be fully enabled by the disclosure material in this application to practice the invention in all of its unique facets.
The various features and advantages of the present invention, including those generally set forth above, will become more fully apparent as the description of the invention which now follows below in detail is read in conjunction with the accompanying drawings.